虚拟模板/硅胶表面分子印迹材料的制备及其在海水溶液中的吸附行为研究

Synthesis,Evaluation and Adsorption Behavior of Naphthalene Analog-Imprinted Polymer by Immobilized Template on Modified Silica Gel in Seawater

以萘乙酸为虚拟模板,以甲基丙烯酸为功能单体、二甲基丙烯酸乙二醇酯为交联剂,用表面聚合-牺牲硅胶法合成了孔状结构的萘分子印迹聚合物。采用红外光谱、扫描电镜和N2吸附实验对印迹聚合物进行了表征;运用理论化学计算探讨了功能单体的筛选方法;利用平衡吸附法考察了印迹材料对海水中萘、蒽、菲化合物选择识别特性。实验表明:以α-萘乙酸分子为模板的分子印迹聚合物对萘具有较好的识别能力。另外,由于α-萘乙酸分子中羧基的存在,使得分子印迹聚合物(MIP)的印迹空穴又与菲的体积大小相匹配,所以也表现出对菲的独特吸附能力。制备的印迹材料可望用于海水中2～3环多环芳烃的选择性吸附与富集。

A novel surface imprinting material was synthesized using a template immobilized on a modified Silica gel matrix where naphthyl acetic acid was grafted to aminopropyl Silica. The Silica template conjugate was co-polymerized with a functional monomer （methacrylic acid） and cross-linker （ethylene glycol dimethacrylate）,and then the Silica-polymer composites were treated with an aqueous NH4HF2 solution to dissolve the Silica matrix. FT-IR spectrum and scanning electron microscope （SEM） were adopted for the characterization of the surface and structure of the molecularly imprinted polymer,also,the specific surface area of molecularly imprinted polymer （MIP） were studied. The binding energy of imprinted molecule with functional monomer was calculated by using the density functional theory （DFT） method,and the largest binding energy could be chosen for the synthesis of MIP. Competitive rebinding test was carried out in seawater media,and the selective adsorptions of target molecule on MIP were studied. The resulting polymer was found as specific affinity toward naphthalene and phenanthrene. The reason for the higher sensitivity to phenanthrene owe to the size of the carboxyl group,where the imprint molecule was larger than naphthalene. It is was possible to preconcentrate the structural analogues of naphthalene from seawater by using the analog-imprinted polymer in the future.